Because they were able to successfully treat a greater number of sites in these patients, the research team is now planning a follow-up study that will enroll patients with up to 10 metastatic lesions, called SABR-COMET-10.
"We don't know the upward limit of how many tumors can be treated with SABR," he said. "The concern is the amount of radiation exposure a patient can tolerate. We don't know yet what the safe boundaries are. We've been very conservative, as this is a new technology."
Nearly half (46 percent) of the patients treated with stereotactic radiation were still alive after five years, compared to 24 percent in the control group, said Dr. Palma—a result that he believes will encourage physicians to consider SABR as a treatment option.
"Ultimately, the question of whether an oncologist will offer this treatment as the standard of care for oligometastatic patients will be up to that oncologist," he said. "At the very least, physicians should be considering this as a treatment option for their patients."
"Stereotactic radiation therapy can increase how long these patients live and how long they live without their cancer coming back, and it doesn't seem to have a detrimental impact on their quality of life."